A conventional dispensing system for supplying heated adhesive (i.e., a hot-melt adhesive dispensing system) generally includes a melter configured to receive adhesive in solid or semi-solid form and then heat and/or melt the adhesive, a pump in communication with the melter for driving and controlling the dispensation of the heated adhesive out of the melter, and one or more adhesive dispensing devices (e.g., guns or modules) receiving the heated adhesive from the pump. One or more hoses or manifolds may also be included in the dispensing system to direct the heated adhesive between the melter, pump, and dispensing devices. One particular type of melter used with conventional dispensing systems is a tank melter which includes a relatively large tank for storing molten adhesive that is to be delivered as needed by the dispensing devices. The tank delivers molten adhesive into a manifold located adjacent to the tank, and the pump is generally connected to this manifold to control flow of adhesive at a location immediately downstream from the tank. In order to allow for maintenance of the pump, should such maintenance become necessary, the pump is typically directly connected with bolt fasteners or a similar method to a wall of the manifold.
In embodiments where the pump is mechanically actuated, like a gear pump, a motor must be operatively coupled to the pump for driving the pump. The motor should be shielded from the heat energy applied by the molten adhesive to the pump. As a result, the motor is separately coupled to a frame of the melter and a drive coupling is positioned between the motor and pump to deliver driving rotations of the motor to the pump. In addition to acting as a thermal barrier between the motor and pump, the drive coupling is designed to compensate for shaft misalignment of the motor and pump. This drive coupling must be able to correct for perpendicularity errors caused by the tolerance and separate mounting of the motor and the pump, as well as axial and angular misalignments. Therefore, the drive coupling that must be used with the pump and motor is expensive and complex to install correctly.
During operation of the adhesive dispensing system, if a fault is detected within the pump, maintenance personnel have to disassemble the drive coupling and remove the motor from the melter frame before access is provided to work on the pump. Then after the pump is fixed or replaced, the complex installation and adjustment of the motor and the drive coupling must be repeated again before the adhesive dispensing system can operate. Each of these disassembly and assembly steps add significant time to the downtime required to repair or replace the pump. Furthermore, the assembly of the drive coupling must be done carefully to avoid further downtime for adjustments to alignment between the motor and pump. On the whole, a routine maintenance of the pump may cause a downtime of as much as an hour. In certain dispensing fields such as nonwoven article manufacturing where the adhesive dispensing system produces up to $10,000 worth of product per minute, a significant downtime for maintenance can be financially significant. Thus, any unnecessary downtime of the adhesive dispensing system should be minimized or eliminated.
For reasons such as these, an improved assembly and process for mounting a pump, motor, and drive coupling onto an adhesive melter of a dispensing system would be desirable.